TY - JOUR
T1 - Ionotropic glutamate receptor mRNA editing in the prefrontal cortex
T2 - No alterations in schizophrenia or bipolar disorder
AU - Lyddon, Rebecca
AU - Navarrett, Scott
AU - Dracheva, Stella
N1 - Funding Information:
This study was supported by the Department of Veterans Affairs (VA), Veterans Health Administration, Office of Research and Development, Biomedical Laboratory Research and Development, by a VA Merit award (S. Dracheva), NIMH/NIH grant MH090352 (S. Dracheva), a grant from the American Foundation for Suicide Prevention (S. Dracheva) and by the VISN3 Mental Illness Research and Education Clinical Center (S. Dracheva). Postmortem brain tissue was donated by The Stanley Medical Research Institute.
PY - 2012/6
Y1 - 2012/6
N2 - Background: Dysfunction of glutamate neurotransmission has been implicated in the pathology of schizophrenia and bipolar disorder, and one mechanism by which glutamate signalling can be altered is through RNA editing of ionotropic glutamate receptors (iGluRs). The objectives of the present study were to evaluate the editing status of iGluRs in the human prefrontal cortex, determine whether iGluR editing is associated with psychiatric disease or suicide and evaluate a potential association between editing and alternative splicing in the α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) iGluR subunits' pre-mRNA. Methods: We studied specimens derived from patients with antemortem diagnoses of bipolar disorder (n = 31) or schizophrenia (n = 34) who died by suicide or other causes, and from psychiatrically healthy controls (n = 34) who died from causes other than suicide. The RNA editing at all 8 editing sites within AMPA (GluA2-4 subunits) and kainate (GluK1-2 subunits) iGluRs was analyzed using a novel real-time quantitative polymerase chain reaction assay. Results: No differences in editing were detected among schizophrenia, bipolar or control groups or between suicide completers and patients who died from causes other than suicide. The editing efficiency was significantly higher in the flop than in the flip splico-forms of GluA3-4 AMPA subunits (all p < 0.001). Limitations: The study is limited by the near absence of specimens from medication-naive psychiatric patients and considerable variation in medication regimens among individuals, both of which introduce considerable uncertainty into the analysis of potential medication effects. Conclusion: We found that iGluR RNA editing status was not associated with bipolar disorder, schizophrenia or suicide. Differences in editing between flip and flop splicoforms suggest that glutamate sensitivity of receptors containing GluA3 and/or GluA4 flop subunits is moderated as a result of increased editing.
AB - Background: Dysfunction of glutamate neurotransmission has been implicated in the pathology of schizophrenia and bipolar disorder, and one mechanism by which glutamate signalling can be altered is through RNA editing of ionotropic glutamate receptors (iGluRs). The objectives of the present study were to evaluate the editing status of iGluRs in the human prefrontal cortex, determine whether iGluR editing is associated with psychiatric disease or suicide and evaluate a potential association between editing and alternative splicing in the α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) iGluR subunits' pre-mRNA. Methods: We studied specimens derived from patients with antemortem diagnoses of bipolar disorder (n = 31) or schizophrenia (n = 34) who died by suicide or other causes, and from psychiatrically healthy controls (n = 34) who died from causes other than suicide. The RNA editing at all 8 editing sites within AMPA (GluA2-4 subunits) and kainate (GluK1-2 subunits) iGluRs was analyzed using a novel real-time quantitative polymerase chain reaction assay. Results: No differences in editing were detected among schizophrenia, bipolar or control groups or between suicide completers and patients who died from causes other than suicide. The editing efficiency was significantly higher in the flop than in the flip splico-forms of GluA3-4 AMPA subunits (all p < 0.001). Limitations: The study is limited by the near absence of specimens from medication-naive psychiatric patients and considerable variation in medication regimens among individuals, both of which introduce considerable uncertainty into the analysis of potential medication effects. Conclusion: We found that iGluR RNA editing status was not associated with bipolar disorder, schizophrenia or suicide. Differences in editing between flip and flop splicoforms suggest that glutamate sensitivity of receptors containing GluA3 and/or GluA4 flop subunits is moderated as a result of increased editing.
UR - https://www.scopus.com/pages/publications/84862599144
U2 - 10.1503/jpn.110107
DO - 10.1503/jpn.110107
M3 - Article
AN - SCOPUS:84862599144
SN - 1180-4882
VL - 37
SP - 267
EP - 272
JO - Journal of Psychiatry and Neuroscience
JF - Journal of Psychiatry and Neuroscience
IS - 4
ER -